Cleaned up kernel.h; the insque(), remque() functions are now in a separate

header kqueue.h - together with their implementation which was in module.c
Added a new CHECK_USER_ADDRESS() macro that can be used to check if a
user address points into the kernel.


git-svn-id: file:///srv/svn/repos/haiku/trunk/current@1742 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/private/kernel/kqueue.h

@@ -0,0 +1,45 @@
+/* 
+** Copyright 2002, Axel Dörfler, [email protected]. All rights reserved.
+** Distributed under the terms of the OpenBeOS License.
+*/
+#ifndef KQUEUE_H
+#define KQUEUE_H
+
+
+/* The object that is put into a queue must begin with these
+ * fields, but it doesn't have to be this structure.
+ */
+struct quehead {
+	struct quehead *next;
+	struct quehead *prev;
+};
+
+
+/** Inserts an element (a) to the queue (b) */
+
+static inline void
+insque(void *a, void *b)
+{
+	struct quehead *element = (struct quehead *)a,
+		 *head = (struct quehead *)b;
+
+	element->next = head->next;
+	element->prev = head;
+	head->next = element;
+	element->next->prev = element;
+}
+
+
+/** removes an element from the queue it's currently in */
+
+static inline void
+remque(void *a)
+{
+	struct quehead *element = (struct quehead *)a;
+
+	element->next->prev = element->prev;
+	element->prev->next = element->next;
+	element->prev = 0;
+}
+
+#endif	/* KQUEUE_H */